Why did the transcontinental railroad start?
The government needed a faster way to transport troops and mail. Settlers wanted to travel faster. Farmers need to transport their goods faster and more cost efficient.
The transcontinental railroad was built by the Union Pacific Railroad going west from Omaha, Nebraska. They built their part of the railroad to Promontory, Utah. The Central Pacific Railroad built the other part of the transcontinental railroad starting in Sacramento, California and built east meeting the Union Pacific Railroad.